This invention relates to a converter for converting optical data input in parallel directly to that in serial.
The conversion of the optical data in parallel into the optical data in serial, similarly to the conversion of an electric signal from parallel to serial, has been considered as important signal processing technology.
Usually in a general converter for performing the parallel-serial conversion of optical data, a conversion method has been used such that parallel optical data is once converted into a parallel electrical signal then converted into a serial electrical signal and further converted into the optical data, finally resulting in serial optical data obtained from the parallel optical data. However, a conventional converter of this kind has a number of problems.
(a) Two conversions, such as light.fwdarw.electricity and electricity.fwdarw.light must be performed, for which the delay time required for the conversion is accumulated to increase the time of parallel-serial conversion. PA1 (b) Low efficiency of mutual conversion between light and electric signals causes a remarkable decrease of output light intensity, resulting in the necessity for amplifying the light. PA1 (c) The necessity for providing a circuit to electrically perform parallel-serial conversion causes complicated circuit construction. PA1 (d) In case of integration for the converter, the hybrid forming of the whole substrate requires a very high level of manufacturing technology.